Traditionally, molded aerated frozen bars, ice cream, or water ice are manufactured by partially freezing an ice cream mix, ice milk mix, frozen yogurt mix, water ice mix, or fruit juice mix in conventional batch or continuous freezers followed by pumping and filling the mix into molds of different shapes and sizes. During the last decade, a new generation of freezers has been developed which are equipped with pre-whippers that enable the mix to be pre-aerated before being partially frozen in the freezer. The molded products are usually quiescently frozen using a cold brine system at −30° C. to −40° C. If desired, after demolding, the molded products may be coated with chocolate or compound coating. Finally, the products are usually packaged and stored at about −30° C. until transport and distribution.
This traditional process for manufacturing molded aerated frozen bars, ice milk, yogurt, ice cream, or water ice has limitations. For example, the partial freezing of the mix in the freezer, followed by quiescent freezing in the molds, leads to the formation of an icy texture, loss of air, and formation of large air cells in the product having a size range of about 110-185 microns (Arbuckle, W. S. Ice Cream, Fourth Edition, 1986, Van Nostrand Reinhold, New York, p 234). Shrinkage of the products is often a problem and when eating the product, a very cold feeling in the mouth is experienced. Furthermore, it is difficult to achieve more than 20% overrun in water ice, a typical overrun is from 0% to 20% and usually is about 5%. It is very difficult to achieve more than 80% overrun and almost impossible to achieve an overrun of 120% or higher in finished ice cream products using conventional manufacturing.
Non molded products have similar problems. Air cells and ice crystals start growing immediately after production of non molded products. Significant air cell and ice crystal growth occurs during transportation, storage at the grocery store or during transportation and storage of the products by the consumer. None of the available non molded ice cream or water ice products inhibit or delay air cell or ice crystal growth after production or during hardening, transportation, or distribution.
Currently, there is no process that can produce very stable finely aerated frozen ice cream, ice milk, yogurt, or water ice having an average air cell size of less than 50 microns and an average ice crystal size of 25 microns or that are heat shock resistant for a period of time after production. Thus, there is a need for finely aerated ice cream, ice milk, yogurt or water ice that maintain a smooth texture, do not suffer from shrinkage, do not give a very cold feeling in the mouth, have an uniform appearance without large air pockets on the surface and have a significantly higher heat shock resistance. Moreover, no process can produce a stable overrun of more than 20% to about 100% for water ice products or an overrun between about 20% to about 250% for ice cream products. The present invention provides products and processes which overcome these disadvantages.